Telltale device



A. MAYER TELLTALE DEVICE May 25, 1948.

Filed Jan. 15, 1948 .r n MW m m VM r cm 4 y u m 0 HM? C Patented May 25, 1948 Pill- ED STATES PATENT err-Pics TELLTALE DEVICE AugnstineMa-yer,Jackson Heights, N. Y, assignor to ltiorse .Boulger Destructor Company, New "York, N. Y., a'corp'oration of Delaware Application January 15, 1948, S'erial?No.- 2; t62

G-Ciaims. 7.1

This invention relates to telltaledevices-adapted to be employed in closed or open containers or bins which are designed to receivemobile material of-granular, pulverulent, flocculentor sim ilar nature.

In systemstfor storing and conveying: dry granular or pulverulent materialthere are usuallyemployed containersor bins into which thematerial isfirst charged after which the ma-terialis removed. For example, in pneumatic systems for conveying material such 'asdry cement :orother mobile pulverulentor granularimaterial, the material' ischarged from a suitable source into a receptacle or container, and when the receptacle is filled the receptacle is arranged :so that vthe charge may be removed from the receptacle and conveyed through conduits to'another place-by means of compressed 1 air, the material being-carriecl through the conduit with the -moving:stream of air. Frequently such systems are closed systems'and it is important to know when :the receptacle, which receives :the material to be blown therefrom, is rfilledwithsmaterial. It-is impractical'if not impossible tosce inside the receptacle to observe when the material "being charged into it has reached .a predetermined level and, furthermore, even if the receptacle were such that the orise in level of the material could be seen, it would require personalrattention for observation and "this takes'time-which might otherwise be-taken-up in more useful work.

It is an object of this :invention to'provi'de a telltale device which will eliminate the abovementioned'drawback by providing a telltale device which is adapted for use in open or closed receptacles, containers or bins, and'wh-ich-is actuated by the-mobile-material being charged into such receptacle to give-a visual or audible signal outside at a place-near to-or remote-from it to indicate when'them'aterial being charged reaches a predetermined levelor when a predetermined amount has been charged, or to indicate the height of material in 'acontainer.

According to the invention, there is provided a device of novel construction :wherein a shell is suspended from above one :fiexible hanger :and in which there is mounted a plurality of switches, preferably -mercury "switches, which will close an electrical circuit upon tilting, the switches being connected in a circuit -=with :a signal and arranged about a vertical axisin suchimanner that movement of the axis from-thevertical will cause at least one of the switches to close the electrical circuit and thereby actuate-thersignal.

Although the novel vfeatures which are believed tobe characteristic of the invention will bepointedout in theqannexed claims, the invention itself as to its objects and advantages and the manner in which it maybecarriedout-may be better understood by referenceto the following description-taken in connection with the accompanying drawings forming a part hereof, in which Fig. dis a view showingthemanner of mounting the telltale device in a receptacle of the closed type;

Fig. 2 =is-.alarger scale cross-section view in elevationof the telltaledcvice withsparts broken away;

Fig. 3 is a view -on line 3-3 of Fig. 2; and

F1;ig.v4 is: a wiringidiagramof the electrical cir- Clll Although the :invention is adapted :for use in connection with various forms of receptacles, bins or containers for receiving various kinds of mobile materials, it is herein illustrated in association with a container lfl particularly designed for use iii-handling and pneumatically conveying various materials such as -'dry cement, one type ofapparatus of this sort being disclosed in Letters Patent No. -2,255 ,438, granted September -9,

1 941, to Evelyn G. Robinson.

@Such apparatus, shown somewhat schematicallyJin-Fig. -1, comprises a container Hl'of generally cylindrical shape at its upper end and having a domelike cover H. The cover is provided with acharging conduit i2 equipped with a valve t3 for openingandclosing it. Thebottom end of the container -lfl ispso shaped that its wall it which is "inclined thus forms :an inverted frustrumof .a cone Within the 1 container is an arrangement whereby compressed air may .b'eiintroduced through theiline l5 and controlled by valvevl'li. "When-thematerial His charged into the container iup -to a predetermined quantity. valve 13 is closed, valve 18 in discharge'line 19 is -'opened and compressed air is introducedthroughline 15; Asdescrl-bed :in further detail in said Robinson patent :the pulverulent materialiis: carriedain thestream of moving: air-through the -.discharge;conduit and *may :be transported to -'another place.

In the 'cou'rse ofpperating this sort of apparatus it is- "desirable :to know when -a proper amount .of material :H has beenwhargedinto the container Ill eth'roug'lrthe charging conduit-l 2. The device of this invention A is admirably -suited tovthepurpose. fItcomprisesa-shell 20 suspended on a flexible cable 32 which is-lsecuredto the top cover of thecontainer :Hl-as shown in Fig. 1.

Within the shell 2|] is mounted a plurality of mercury switches 2| connected to wiring which extends through a suitable opening in a mounting member 22 secured to the cover H. The wiring is connected in circuit with a suitable source 23 of electric current and, as shown, is provided with a lamp 24 which lights up when the circuit is closed. Of course, other types of signal or relays may be used in place of the lamp, and the telltale device can also be used with a circuit for initiating operation of automatic controls.

The shell is preferably made of aluminum although other material may be used. It is of hollow dome or bell shape and terminates in a neck 25. A disc 25 having a central Opening 21 closes off the neck portion 25 and also provides means for supporting the switch shelf 28, as described hereinafter. An inverted cup-shaped cap 29 is mounted on the neck portion 25 and it has a central opening 30 in its cover part 3| through which extends the flexible hollow supporting cable 32. The inverted cup is removably secured to the neck 25 by set screws 33.

The bottom opening of the bell-shaped shell 23 is covered with a (circular disc 34 and is preferably mounted securely at its periphery 35 by clamping it between rolled flanges 36 and 31 formed at the periphery of the shell as shown in Fig. 2. The'bottom closure disc 34 is provided with a central opening 38 which is provided with a wire screen 39 mounted on a flanged ring 40 having a peripheral flange by which it may be securely clamped to the disc 34 around the edge of the central openin 38. An air pervious cloth filter 4| is superimposed on the wire screen 39. Thus the interior of the shell 28 communicates with the outside through the cloth filter 4|. This permits the use of the device within closed containers where the pressure may be high and allows for equalization of the pressure inside and outside the shell and at the same time the filter pre vents dust or other particles from getting inside.

The horizontally disposed switch supporting shelf 28 is mounted at its center on a hollow threaded nipple 42. The shelf is clamped between an upper nut 43 and a lower nut 44 threaded on the nipple. The nipple is supported at its upper end between two clamping nuts 45 and 45 which engage the disc 26 at the neck of the shell.

The flexible cable 32 which is used to suspend the device from above is made of spring wire 33 wound in helical fashion as shown more clearly in Fig. 2, thus to provide a substantial length of flexible LhOllOW cable, the wall of which comprises the helically wound wire. The lower end of this flexible hollow cable 32 fits over the upstanding end portion of the threaded nipple 42 and is secured to it. The upper end of the flexible cable is secured to the mounting member 22. Hence, when the device is hung as shown, for example, in Fig. 1, the shell is free to be tilted off its vertical axis by reason of the flexibility of the suspending cable 32.

Mounted upon the supporting shelf 28 are a plurality of mercury switches-2l horizontally disposed and arranged circumferentially about the axis of the hollow supporting nipple 42, four such switches being shown. These switches are removably mounted in spring clips which are secured to the shelf by bolts 5|. The -clips have upstanding prongs 52 which grip the glass mercury switches and thus provide means for easy replacement of the switches. r Y

The switches are connected in parallel in the electrical circuit as shown in the wiring diagram Fig. 4. Lead-in wire 55a is connected to contact 56a of switch He and to wire 51; lead-in wire 49a is connected to contact 58a of switch 2 la and to wire 59; lead-in wire 55b is connected to contact 56b of switch 211) and to wire 51; lead-in wire 49b is connected to contact 582) and to wire 59; switches 21c and 21d are connected in similar fashion, as shown in the wiring diagram. The lead-in wires 55a, 55b; 49c and 55d are suitably connected to the wire 51 and lead-in wires 49a, 49b, 55c and 49d are connected to wire 59 above the shelf 28 and wires 51 and 59 are then passed through a suitable opening 48 through the shelf and then passed up through the hollow nipple 42 and hollow flexible cable 32. Wires 5'! and 59 are then connected in the circuit with source of current 23 and lamp 24 on the outside of the container Ill.

The operation of the device is as follows: When the device is hung in a container, such as disclosed in Fig. 1, the normal position of the shell is such that the cable hangs vertically and thus the axis of the rigid nipple 42 is vertical. Consequently, the switch shelf 28 assumes a horizontal position. When the shelf is in horizontal position the mercury 60 lies in the bottom of the glass casing of the switches and does not close the electrical contacts inside and therefore the electrical circuit remains open. However, if the shelf 28 is tilted from the horizontal the mobile mercury in at least one of the switches will assume a position to close the electrical contacts and will thereby close the electrical circuit. when the circuit is closed current flows through it to light the lamp 24.

It may now be assumed that the container is empty and is to be filled and the shell 20 is hanging vertically. In this position no current flows in the circuit. When the material being charged to the container reaches a level high enough to engage the bottom 34 of the shell, the shell will be tipped [off of its vertical axis because the advancing or rising surface of the material 11 will assume its angle of repose and cause the bottom of the shell to be moved off horizontal, thus causing the axis :of the nipple 42 to be tilted and the shelf 28 to be moved off horizontal. The flexible cable 32 allows for this movement. Hence the electrical circuit is closed by one of the mercury switches and the lamp 24 glows to give the signalwhen the container is filled to the desired level at which the shell 20 is placed.

Although the device has been described in connection with a particular type of container or bin, for illustrative purposes, it will be understood that it may be used in other places where it is desirable to have automatic indication of the filling of mobile granular or pulverulent materials or where indication is desired of the height of material in a container. And it will be understood also that the closing of the circuit as described adapts itself to various types of signals or the operation of relays for the initiating and controlling of automatic controls.

The terms and expressions which have been employed herein are used as terms of description and not of limitation and there is no intention in the use of such terms and expressions of excluding any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of invention claimed.

What is claimed is:

1. A telltale device actuatable by engagement with the surface of a pile of pulverulent material which comprises a flexible cable for suspension of the device from above, a rigid switch supporting member secured to the lower end of said cable which in normal position has a vertical axis, a plurality of mercury switches secured to said member, circumferentialy disposed about its axis and assuming a horizontal position when said axis is in vertical position, and an electrical circuit connected to said switches, said flexible cable permitting said member to be tilted from its vertical axis thereby to cause at least one of said switches to close the circuit.

2. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a hollow shell, a switch supporting member within said shell, a flexible cable secured to said shell serving as means to hang said shelf for tiltable movement, a plurality of mercury switches within said shell secured to said supporting member, an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing when said shell is tilted.

3. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a hollow shell, a shelf supporting member within said shell, a horizontally disposed shelf secured to said member, a flexible cable secured to said shell serving as means to hang said shell for tiltable movement, a plurality of mercury switches within said shell secured to said shelf and lying in horizontal position when said shell is hanging freely on said cable and lying in tilted position when said shell is tilted, an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing the circuit when said shell is tilted.

4. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a substantially closed hollow shell, a nipple extending into said shell, means providing a vent in said shell, a flexible cable secured to said shell serving as means to hang said shell for tiltable movement, a switch supporting shelf within said shell secured to said nipple, a plurality of mercury switches within said shell secured to said shelf and circumferentially partially disposed around the vertical axis of said nipple, an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches a closing the circuit when said shell is tilted.

5. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a substantially closed hollow shell having a bottom wall, a hollow nipple extending into said shell, means providing a dust filter vent in said bottom wall, a hollow flexible cable secured to said shell serving as means to hang said shell for tiltable movement, a horizontally disposed shelf within said shell which tilts with tilting movement of said shell, a plurality of mercury switches within said shell secured to said shelf and circumferentially disposed around the vertical axis of said hollow nipple, wiring providing an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing the circuit when said shell is tilted, said wiring connecting said switches extending through said hollow nipple and hollow cable for connection to an outside signal.

6. A telltale device actuatable by engagement with the surface of a rising pile of mobile material which comprises a hollow bell-shaped casing having a neck portion at its upper end, a closure member closing the bottom end of said casing, a closure member for said neck portion, an air pervious filter in said casing providing means for communication between the interior of said casing and the outside, a vertically disposed hollow nipple secured at its upper end to said neck closure member and extending into saidcasing, a horizontally disposed switch supporting shelf secured to the lower end of said nipple, a plurality of mercur switches mounted on said shelf and circumferentially disposed around the vertical axis of said nipple, a hollow flexible cable secured at its lower end to said nipple and extending upwardly from said casing and providing means for hanging said casing for tiltable movement, and wiring connecting said mercury switches, said wiring extending through said nipple and cable to the outside of said casing for connection with a source of electrical current.

AUGUSTINE MAYER.

Certificate of Correction Patent No. 2,442,275. May 25, 1948.

AUGUSTINE MAYER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 6, line 1, claim 4, strike out the word partially; and that the said Letters Patent should be read with this ggection therein that the same may conform to the record of the case in the Patent Signed and sealed this 7th day of September, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commz'ssioner of Pdtents.

Certificate of Correction Patent No. 2,442,275. May 25, 1948.

AUGUSTINE MAYER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 6, line 1, claim 4, strike out the Word partially; and that the said Letters Patent should be read with this gigection therein that the same may conform to the record of the case in the Patent Signed and sealed this 7th day of September, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

